Privacy Friendly Apps - improved privacy protection on the smartphone

We use our smartphone for private conversations, store our contacts and organise our meetings with it. The access to all this sensitive data is handled with the so-called permissions. It means, for example, that each app that requires the smartphone camera needs to get the corresponding permission first. Many of the apps, especially free ones, however, request permissions that are not necessary for their functionality. As such, for example, a Torchlight app might request access to one’s contact list, or a QR-code scanner can send private photos to some server.

It is often not clear to the end users, however, whether and when these permissions may lead to privacy violations. Even if sharing some personal data does not seem dramatic, collecting and analysing much of this data can be abused. As such, hackers can use the collected data in order to get more inforamtion about you, which can then be used for targetted attacks (so-called spear phishing), or for influencing one’s buying or voting decisions. Even if the app developer itself is trustworthy, it can become a target of a hacker attack, so that all of the collected data becomes compromised.
Therefore, in order protect one's privacy and ensure that the sensitive data on one's smartphone is not compromised, it is important to consider the permissions that the installed apps require. This is particularly critical for older devices with an Android version before Android 6.0, since the permissions cannot be individually denied there. In order to provide privacy-friendly alternatives to apps, that often require permissions not necessary for their functionality, Privacy-Friendly Apps are proposed.
"Als Datenschützer begrüße ich sehr, dass die Forschungsgruppe SECUSO Apps entwickelt hat, die nicht nur Open Source angeboten werden, sondern vor allem Daten lokal speichern und die Nutzer nicht überwachen." (Dr. Stefan Brink, Landesbeauftragter für den Datenschutz und die Informationsfreiheit Baden Württemberg)

What are the advantages of Privacy Friendly Apps?

Privacy Friendly Apps do not contain any kind of advertisement or tracking mechanisms. So user data is neither recorded nor sent to any third party.

All source codes of Privacy Friendly Apps are publicly available in the internet on the github platform (Link to So anybody could proof that the software solely has the properties mentioned in the description. The property is called Open Source and the choosen Open Source lisense (GPLv3) allows anybody to refine or enhance the applications as long as they are published under the same lisense.

Summary: All Privacy Friendly Apps:

  • are Open Source (GPLv3) and their source code can be viewed an Github by anybody
  • used minimal permissions
  • do not neither tracking mechanisms nor advertisement

Besides the Google Playstore the Privacy Friendly Apps are available in the F-Droid Store as well. F-Droid is an alternative app store for Android applications, which offers in its standard repository only apps with open source code. The source code of any F-Droid application is publicly available. Whenever possible F-Droid compiles the application from the code by itsself. So it is ensured that the application actually belongs to the source code. During this procedure F-Droid checks the application regarding security issues (e.g. bugs) and privacy issues (e.g. tracking mechanisms).

F-Droid can be used without an extra account, it does not store any user data. Unfortunately, it is not available in the Google PlayStore, so it has to be installed by the user manually. To do so the store application can be downloaded under . Before installation it must be assured that the installation of software from unknown sources is allowed on the smartphone. This can be done under Settings > Security


Privacy Policy

The privacy policy for the Privacy Friendly Apps can be found here.



All of these apps can be found in the Google Play Store and in the F-Droid Store for open source software as well.

More information can be found on the web sites of the corresponding app:

Fitness and Health

interval timerInterval Timer and Circuit Training pain diaryPain Diary pausing healthilyPausing Healthily
foodtrackerFood-Tracker active pauseAktivpause to go    


torchlightTorchlight qr scannerQR Scanner notesNotes shopping listShopping list
tape measureTape Measure and Ruler todo listTo-Do-List finance managerFinance Manager tape measureBackup


memo gameMemo Game sudokuSudoku dicerDicer checkersCheckers
game of diceGame of Dice ludoLudo battleshipsBattleships reckoningReckoning Skills
solitaireSolitaire boardgame clockBoardgame Clock minesweeperMinesweeper 20482048


password generatorPassword Generator pin mnemonicPIN Mnemonic


In our archive you will find all apps that we currently no longer support. The support of these apps was discontinued due to too high maintenance effort. The source code of the apps will still be available on GitHub. Interested users can still download the app from GitHub to use them.

We are always happy to hear if someone likes to take over the maintenance of the apps as part of a mentorship. You can find more information on mentorship options here.

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